Afarmer planted 1/8 of his land with beans 1/4 with corn 3/10 with wheat and left the rest unplanted what percentage of his land did the farmer leave unplanted

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).